Experiments upon Swedes. 17 



from bones, does not hasten the germination of turnip-seed, but 

 rather the contrary. 



I would observe, however, that when fairly up the plants 

 manured with superphosphate grew much more vigorously than 

 the others, and soon were twice as big as the rest. Although 

 superphosphate does not promote a more rapid germination of 

 the seed, it is yet extremely useful in favouring a vigorous growth 

 of the plant, thereby bringing the crop out of reach of the 

 turnip fly. 



2. Field Experiments made in 1857. 



The negative results obtained in 1856 with sulphate of am- 

 monia induced me to try this salt again, as well as gypsum 

 and phosphates, arid phosphates in conjunction with sulphate 

 of ammonia, in another part of our farm. It occurred to me, 

 that probably the unfavourable results with sulphate of am- 

 monia might have been due to an excess of this powerful ma- 

 nuring substance having been employed in my experiments in 

 1856. It will be remembered that I applied sulphate of am- 

 monia at the rate of 6 cwt. per acre, a quantity which, con- 

 sidering the inconsiderable depth of the experimental field, may 

 be called excessive. 



It is remarkable, however, that in conjunction with soluble 

 phosphate, sulphate of ammonia proved equally inefficient, 

 showing neither a beneficial nor the contrary effect. In order to 

 study the effects of small quantities of ammoniacal salts on the 

 turnip crop, I used only 1^ cwt. per acre in my experiments 

 made in 1857. In conjunction with these more theoretical 

 experiments, I instituted several others with fertilizers much 

 recommended as turnip-manures. The field selected for the 

 experimental trials with these manures was somewhat deeper, 

 more level, and altogether rather better than the experimental 

 field in 1856. A portion of the soil taken from a large sample, 

 from different parts of the field, was submitted to analysis, and 

 the following results obtained : 



Composition of Soil from Experimental Field, No. 19, of the Royal 

 Agricultural College Farm, Cirencester. 



Moisture (when analysed) 1*51 



Organic matter and water of combination . . 11*08 



Oxides of iron and alumina 14*25 



Carbonate of lime 10*82 



Sulphate of lime -71 



Magnesia *51 



Potash (soluble in acid solution) *32 



Soda ditto ditto *05 



Phosphoric acid *10 



Insoluble silicious matter (chiefly clay) .. 61*78 



101*13 



c 



